A concatenation expression consists of two operands separated by the concatenation operator.
- Both operands must be of the same class, except that a figurative constant may be specified as one or both operands. Neither
operand must be numeric. Neither literal-1 nor literal-2 must be a figurative constant that begins with the word ALL.
- The length of the value resulting from concatenation must be less than or equal to 160 character positions.
- The class of the concatenation expression resulting from the concatenation operation must be:
- When one of the operands is a figurative constant, the class of the literal or concatenation expression that constitutes the
other operand, or
- When both of the operands are figurative constants, the class alphanumeric, or
- The same class as the operands.
- The value of a concatenation expression must be the concatenation of values of the literals, figurative constants and concatenation
expressions of which it is composed.
- A concatenation expression must be equivalent to a literal of the same class and value, and may be used anywhere a literal
of that class may be used.